%I #6 May 28 2016 10:26:08
%S 1,1,1,2,6,24,120,720,5040,40320,362880,1814400,13305600,119750400,
%T 1245404160,14529715200,186810624000,2615348736000,39520825344000,
%U 640237370572800,6082255020441600,81096733605888000,1277273554292736000,22480014555552153600
%N Number of 9-ary heaps on n elements.
%H Alois P. Heinz, <a href="/A273696/b273696.txt">Table of n, a(n) for n = 0..472</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/D-ary_heap">D-ary heap</a>
%Y Column k=9 of A273693.
%K nonn
%O 0,4
%A _Alois P. Heinz_, May 28 2016